The overall aim of this proposal is to identify small molecule inhibitors of glutaminase through high throughput screening (HTS) of the NIH chemical library. Glutaminase has been identified as a target for the treatment of cMyc-expressing cancers where the up-regulated enzyme has recently been shown to play a critical metabolic role promoting cancer cell growth. Glutaminase has also recently been shown to be up-regulated in activated macrophages/microglia and its inhibition limits glutamate release and provides neuroprotection in inflammatory neurological disorders such as HIV1-associated dementia and multiple sclerosis. To date there are no known potent and selective glutaminase inhibitors available. We propose to screen the NIH chemical library to obtain "hits" that could be used as tool molecules to further study the pharmacology of this target as well as serve as leads for further chemical optimization into drug-like inhibitors for clinical development. PUBLIC HEALTH RELEVANCE: Glutaminase has recently been shown to be up-regulated in cancer cells and activated microglia in inflammatory neurological disorders such as HIV1-associated dementia and multiple sclerosis. Genetic approaches which decrease glutaminase have been shown to inhibit cancer cell proliferation and provide neuroprotection. To date, however, there are no selective small molecule inhibitors of this enzyme. Identification of new glutaminase inhibitors would provide a novel therapeutic strategy for these diseases.